Make sure you backup your game before you install this. There have been a lot of reports on the official TS3 forums that it screws up their game because the demo is connected with the actual install of your game.
http://forum.thesims3.com/jforum/posts/list/437793.page
http://forum.thesims3.com/jforum/posts/list/437793.page
Unfortunately I got the memo too late. I should've known better though. All of the store content is gone. As far as I can tell I still have all my CC though. Will experiment some more since now it's all gone to hell anyways.
yes so it seems it does. i had to reinstall my mods (i think thats what fixed them) but if you are using your launcher just go to your downloads section and select all > install to reinstall everything.
apologies if im repeating something someone else said.